Political leaders welcomed BP's report of success in the static kill operations on the Gulf oil well, while some Gulf residents remained apprehensive about a report saying that roughly three-quarters of the leaked oil was gone. Judy Woodruff speaks with the president's chief assistant on energy and climate change, Carol Browner.

JUDY WOODRUFF: More now on these developments from President Obama’s chief assistant on energy and climate change, Carol Browner. She was in the White House Briefing Room when I spoke with her a short time ago.

Carol Browner, thank you very much for talking with us.

CAROL BROWNER, assistant to the president for Energy and Climate Change: Thank you for having us.

JUDY WOODRUFF: So, is this well now history?

CAROL BROWNER: Well, we certainly got some good news today. The static kill, the mud was pumped down. That’s holding. We feel quite confident we won’t see any more oil leaking from this well. We still need to complete the relief well, which is probably another two weeks or so.

But then we have to stay focused on restoring those communities, restoring the environment. We’re going to be in the Gulf for a very, very long time.

JUDY WOODRUFF: But the relief well is still needed?

CAROL BROWNER: Yes, the relief well is still needed.

What the scientists are debating today is whether we could put cement down the top of the old well and then cement in through the relief well. In any event, we have to PUT cement in through the relief well. And so that is another probably two weeks away.

JUDY WOODRUFF: Now, the report the government issued today about the oil that did leak over the last few months, 200 million gallons, three-fourths of it, we are told, has either evaporated or dispersed or skimmed or otherwise disappeared. How reliable is that report?

CAROL BROWNER: Well, a group of government scientists looked at all of the information that we had. They drew some conclusions from it. That was then shared with outside scientists, academics, others, some industry experts.

And what everyone agrees is that about a third of the oil was actually cleaned up. It was contained. It was skimmed. It was burned. It was dispersed. Another big chunk, about a quarter, Mother Nature took care of through evaporation. It was dissolved.

And then there is about a quarter that we call residual. And that doesn’t mean that it’s still out there waiting to come ashore. It just means that it’s not in one of the categories. It’s weathering. Some of it has already come ashore and been cleared. Some of it may come ashore in the form of tar balls.

But what we wanted to do was show the American people what had happened to the oil, the effect of the containment, of the cleanup activities, of the dispersants, of nature — of Mother Nature doing her job.

JUDY WOODRUFF: Well, I ask how reliable those numbers are because some people woke up this morning and said, wait a minute, the biggest accidental spill in history, and three-quarters of it is gone?

We talked to a boat captain and others today in the Gulf area who said they just don’t believe the government anymore.

CAROL BROWNER: Well, this is all available. They should go to the NOAA Web site. There are other scientists who have looked at it who concur in these numbers.

You know, we’re not asking them to simply believe us. We’re sharing with them information that we think is important. We’re sharing that information in its entirety. You know, we do know that 17 percent of the oil was captured. We know because it was put in vessels and it was brought onshore.

We know what happened with skimming, because, again, it was picked up. We know, when the burns happened, how much had been corralled for the burns. So, we have some very, very good numbers in terms of activities out there. In other instances, if the scientists weren’t quite so sure, they accounted for that in the residual.

So, I think this is — I mean, we have believed from the beginning, Judy, that the public had a right to know anything that we knew. And so, as numbers have emerged, whether it be the flow rate — the early numbers were based on very, very simple calculations. As the calculations got more sophisticated, we made those numbers available.

It could be that some of these numbers change. The amount put on vessels won’t change, but some of them may change. And we will make that available.

JUDY WOODRUFF: So, where is the residual oil, the oil that is still there? Where is it? And how much of a threat is it to the environment, to people, to wildlife?

CAROL BROWNER: So, that category called residual, some of that has already come onshore and has been cleaned up. There are many, many tons of oil, sandy oil, oil in reeds and marshes, that’s already been cleaned up and taken out.

Some of it may come on in the form of weathered oil, tar balls. You know, the good news is, nothing has leaked for almost two weeks now. So, nature continues to do its job in terms of biodegrading, breaking this down. The stuff that is very weathered, when it comes on, it can be easier to clean up.

We’re going to be — remain vigilant. We’re going to continue to direct BP to spend the money to get the beaches cleaned up if oil does come ashore. We’re not going away.

JUDY WOODRUFF: And the oil that was chemically dispersed. We saw 8 percent of it was disposed of that way, a lot of concern about the long-term effects of those chemicals. How much is known about that?

CAROL BROWNER: Well, obviously, they have — we have been studying. Those chemicals were studied before they were used. They will continue to study the water column. EPA has conducted now two toxicity tests. Those have been made publicly available. NOAA continues to test.

You know, the decision to use dispersants is always a difficult one. Obviously, oil is toxic. It’s highly toxic in the environment. And so using the dispersants to minimize that toxic impact I think was a good decision. EPA made sure that it was done according to protocols.

And then EPA asked Admiral Allen to issue a directive to lower the amount of dispersants being used. So, a 72 percent reduction in the amount of dispersants that were used at the high point was finally achieved.

JUDY WOODRUFF: And you said a minute ago, Carol Browner, that the government was going to be in the Gulf for a time to come. How much longer is the government going to stay there to look after the well-being of the people, the businesses, the wildlife, the environment in the Gulf?

CAROL BROWNER: We’re not putting a time frame on it. We’re going to stay as long as we need to be there. And you raise all the right issues. It’s the welfare of the people. It’s the economic losses. It’s helping people get back to work, getting the fisheries reopened, making sure that, if any oil, tar balls come onshore, that it’s cleaned up.

We are committed to the Gulf for as long as it takes to make the Gulf, you know, the best it can be. I mean, the people of those communities deserve it. So do the people of our nation. We all enjoy the seafood from the Gulf. This is a national treasure. It’s not just a regional treasure. And we’re going to do everything we need to do to make sure that it is fully restored.

JUDY WOODRUFF: One other question about the chemical dispersants. There have been questions raised about whether the incident commander, Thad Allen, extended too many exceptions in the use of those dispersants. What can you — can you give any assurance on that front?

CAROL BROWNER: Well, I think the most important number for people to look at is the 72 percent reduction in the use of dispersants from its highest point. It was coming down.

That was, I think, in large measure, a testament to Lisa Jackson’s work with Admiral Allen, that they were not using as much as had once been used. You know, clearly, everybody is going to be studying what the oil did to the environment, what the dispersants mean in the environment. You know, there’s a lot to learn from this.

But I think the good news today is, there’s no oil leaking. There’s not going to be oil leaking. And we have given the public an accounting of where the oil went.

JUDY WOODRUFF: We’re going to leave it there.

Carol Browner, adviser to the president on energy and climate change, thank you.

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